An image pickup circuit including a plurality of circuit blocks. Each of the plurality of circuit blocks includes a plurality of comparing elements, a single counter, and a plurality of storage units. Each of the comparing elements compares a pixel signal supplied through a vertical signal line connected to vertically aligned pixels in a plurality of pixels arranged in a matrix, and a slope signal whose voltage is changed from an initial voltage at a constant slope. The counter counts an elapsed time since a voltage of the slope signal starts to change from the initial voltage. Each of the storage units stores a count value obtained by the counter in accordance with a comparison result of the comparator, the count value corresponding to an elapsed time until the voltage of the slope signal is changed from the initial voltage to a voltage coinciding with the pixel signal.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An imaging device comprising: a pixel array including a plurality of pixels; a plurality of signal lines coupled to the plurality of pixels; a plurality of comparators coupled to the plurality of signal lines and arranged in columns, the plurality of comparators including: a first comparator in a nth column; a second comparator in a (n+1)th column; a third comparator in a (n+2)th column; and a fourth comparator in a (n+3)th column, wherein the first, second, third and fourth comparators are arranged in order along a first direction; a plurality of counters including a first counter and a second counter, wherein the first counter and the second counter are disposed on a same side of the pixel array, wherein the pixel array and the first counter are arranged along a second direction perpendicular to the first direction; and a reference signal generation circuit, wherein the first comparator is coupled to the reference signal generation circuit and the first counter, the second comparator is coupled to the reference signal generation circuit and the second counter, the third comparator is coupled to the reference signal generation circuit and the first counter, and the fourth comparator is coupled to the reference signal generation circuit and the second counter.
2. The imaging device of claim 1 , wherein the plurality of signal lines extend in the second direction.
3. The imaging device of claim 2 , wherein the first counter and the second counter are arranged in the second direction.
4. The imaging device of claim 1 , wherein the imaging device further comprises a plurality of latch circuits.
5. The imaging device of claim 4 , wherein the plurality of latch circuits includes: a first latch circuit arranged between the first comparator and the first counter; a second latch circuit arranged between the second comparator and the second counter; a third latch circuit arranged between the third comparator and the first counter; and a fourth latch circuit arranged between the fourth comparator and the second counter.
6. The imaging device of claim 1 , wherein the plurality of comparators further includes a fifth comparator in (n+4)th column and a sixth comparator in (n+5)th column, wherein the fifth comparator is coupled to the reference signal generation circuit and the first counter and the sixth comparator is coupled to the reference signal generation circuit and the second counter.
7. The imaging device of claim 1 , wherein the plurality of signal lines further includes: a first signal line in the nth column; a second signal line in the (n+1)th column; a third signal line in the (n+2)th column; and a fourth signal line in the (n+3)th column.
8. The imaging device of claim 7 , wherein the first comparator is configured to compare a reference signal from the reference signal generation circuit to a voltage on the first signal line, the second comparator is configured to compare the reference signal to a voltage on the second signal line, the third comparator is configured to compare the reference signal to a voltage on the third signal line, and the fourth comparator is configured to compare the reference signal to a voltage on the fourth signal line.
9. The imaging device of claim 8 , wherein the reference signal is a slope signal having a voltage that changes from an initial voltage at a constant slope.
10. The imaging device of claim 1 , wherein the imaging device comprises a single reference signal generation circuit.
11. The imaging device of claim 1 , wherein the first counter is coupled to a predetermined number of comparators, and wherein the predetermined number is determined by considering a delay due, at least in part, to wire resistance and wire capacity.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
April 19, 2018
December 1, 2020
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.